一、最佳判决电平的确定判决即信号的检测。在光纤数字通信系统中,由于光纤信道以及接收机频率特性和噪声的影响,会使接收端信号波形畸变。这种畸变一般来说是复杂的、随机的。判决的目的就是要克服这种畸变,以便从接收信号中提取所发送的序列。当然,判决电路完全克服畸变是不可能的,这里就要根据最佳检测理论,确定在一定的假设条件下满足某种准则的最佳判决。对于大多数通信系统,感兴趣的最佳准则是最小错误概率准则。下面具体讨论一下在最小错误概率准则下判决电路的错误概率(也称误码率)。设通信系统是二进制的,即只有两个信 First, the determination of the best decision level that the signal detection. In optical fiber digital communication systems, the signal waveform of the receiver is distorted due to the influence of the frequency characteristics of the fiber channel and the receiver and the noise. This distortion is generally complex and random. The purpose of the verdict is to overcome this distortion in order to extract the transmitted sequence from the received signal. Of course, it is impossible for the decision circuit to completely overcome the distortion. Here, we will determine the best decision to satisfy a certain criterion under certain assumptions based on the best detection theory. The best criterion of interest for most communication systems is the minimum error probability criterion. The following specific discussion of the minimum error probability criterion decision circuit error probability (also known as bit error rate). Let the communication system be binary, that is, only two letters